About

Evd is a geometry and event display built using the EVE Environment¹. It loads GDML geometries and ROOT MC truth outputs from both Geant4 Validation App and Celeritas (RootStepWriter) to draw simulated events within the geometry.

Dependencies

• ROOT

Build

$ mkdir build
$ cd build
$ cmake ..
$ make

Run

$ ./evd geometry.gdml [simulation.root] [flags]

Input files and flags

• geometry.gdml: Loads the gdml geometry. This is the only mandatory input.
• simulation.root: Loads the simulation run. Compatible with benchmarks/geant4_validation_app and celeritas::RootStepWriter.
• -vis [vis_level]: Sets the visualization level of the gdml. Higher values = more details. Default: 1.
• -e [event_id]: Event number to be displayed. If negative, all events are drawn. Default: 0.
• -s: Show step points.
• -cms: For cms2018.gdml only. Loads the CMS geometry without the surrounding building and sets the LHC beamline to invisible.

Interface

Keyboard / mouse commands

• Mouse left click: Rotate view.
• cmd + mouse left click: Pan view.
• Mouse/trackpad scroll or j/k: Zoom.
• w/e/r/t: Toggle between different views.
• shift/ctrl: Increase / decrease action rate. Eg. shift + j/k zooms in/out at larger steps. Valid for mouse actions as well.

Event track list

Particle tracks are shown in the event directory and named using the convention [event_id]_[track_id]_[particle_name_or_pdg]. PDG is only used if it is not mapped to a name in MCTruthViewerInterface.

Development notes

The x close button of the evd window causes ROOT to crash. Typing .q in the terminal or using the Quit ROOT option in the Browser menu avoids that.

Footnotes

1. M. Tadel. Overview of EVE – the event visualization environment of ROOT. 2010 J. Phys.: Conf. Ser. 219 042055. ↩